Abstract

Evidence of short-lived episodes of mid-Cretaceous deformation, metamorphism, uplift, and hiatus in sedimentation is widespread in the Lower Cretaceous rocks that bordered the Cretaceous Pacific basin. I present a model in which these coeval but widely spaced events are linked to increased ridge-push force at subduction zones triggered by large-scale upwelling of mantle associated with the mid-Cretaceous superplume. This model can account for mid-Cretaceous terrane accretion and ophiolite obduction events and can explain brief compressional phases in predominantly extensional orogenies as recognized in Alaska, British Columbia, California, western South America, and West Antarctica.